Nitroglycerin preparations or glyceryl trinitrate are used preferably sublingually for the arrest and prophylaxis of angina pectoris attacks, in the case of myocardial infarction, pulmonary oedema, asthma cardiale, coronary sclerosis, spastic migraine and spastic bile duct colic, and lead to a prompt effect on the pain or critical heart-circulatory conditions with a reduced blood flow and increased pressure in the ventricles.
In the case of sprayable aerosol sprays to be applied sublingually, preparations have been used hitherto which contain, in addition to nitroglycerin and customary additives, a neutral oil as vehicle and 70 to 95% by wt. of propellant such as dichlorotetrafluoromethane and are described, for example, in DE-PS 32 46 081. Although these nitroglycerin-containing aerosol preparations guarantee a therapeutically effective blood level within a short period, they have the disadvantage that they can be harmful to the environment because of the fluorochlorohydrocarbon propellants present.
Consequently, propellant-free aerosol preparations were proposed, namely so-called pump sprays e.g. according to DE-OS 39 22 650, in which the liquid phase is composed of aliphatic C.sub.2 to C.sub.4 alcohols and a vehicle. In these nitroglycerin pump sprays, the C.sub.2 to C.sub.4 alcohol content is said to be 51 to 90% by wt. and, moreover, a polyalkylene glycol or a C.sub.2 to C.sub.8 alcohol having several hydroxy groups is said to be provided as vehicle.
Preparations of this kind have the disadvantage that, in view of the high alcohol content, approximately 30% of the output quantity of approximately 50 mg present in the metering chamber of the pump spray device evaporates after only a short storage period, with the result that the first squirt contains only 35 mg of the active substance solution instead of the clinically required quantity of approximately 50 mg. This loss of active substance solution is too great for a drug which is used for the immediate treatment of acute angina pectoris attacks and its use can not, therefore, be justified from a therapeutic aspect. Moreover, a blockage of the valves can also be brought about as a result of the evaporation of ethyl alcohol, which completely precludes the application of a metered dose. In the case of lingual application, the high C.sub.2 to C.sub.4 alcohol and preferably ethyl alcohol content also has the disadvantage that the mucosa in the lingual region is excessively stimulated and the plasma level rises too high very rapidly in comparison with equivalent preparations which have been proven in therapeutic use for decades. This can lead to vasomotor headaches, orthostatic dysregulation, a feeling of weakness or a dazed state. Moreover, drugs with high concentrations of alcohol are unsuitable for certain groups of patients (e.g. pregnant women, persons with alcohol dependency, persons with liver or kidney damage) and give rise to considerable safety problems in production and storage.
Apart from the excessively high ethyl alcohol content of this propellant-free aerosol preparation, a polyalkylene glycol or a C.sub.2 to C.sub.8 polyhydroxy alcohol is proposed as vehicle which are usually irritating to the mucosa or toxicologically harmful.